xref: /linux/fs/xfs/scrub/inode.c (revision 2f804aca48322f02a8f44cca540663845ee80fb1)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2017-2023 Oracle.  All Rights Reserved.
4  * Author: Darrick J. Wong <djwong@kernel.org>
5  */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_trans_resv.h"
11 #include "xfs_mount.h"
12 #include "xfs_btree.h"
13 #include "xfs_log_format.h"
14 #include "xfs_trans.h"
15 #include "xfs_ag.h"
16 #include "xfs_inode.h"
17 #include "xfs_ialloc.h"
18 #include "xfs_icache.h"
19 #include "xfs_da_format.h"
20 #include "xfs_reflink.h"
21 #include "xfs_rmap.h"
22 #include "xfs_bmap_util.h"
23 #include "scrub/scrub.h"
24 #include "scrub/common.h"
25 #include "scrub/btree.h"
26 #include "scrub/trace.h"
27 
28 /* Prepare the attached inode for scrubbing. */
29 static inline int
30 xchk_prepare_iscrub(
31 	struct xfs_scrub	*sc)
32 {
33 	int			error;
34 
35 	sc->ilock_flags = XFS_IOLOCK_EXCL;
36 	xfs_ilock(sc->ip, sc->ilock_flags);
37 
38 	error = xchk_trans_alloc(sc, 0);
39 	if (error)
40 		return error;
41 
42 	sc->ilock_flags |= XFS_ILOCK_EXCL;
43 	xfs_ilock(sc->ip, XFS_ILOCK_EXCL);
44 	return 0;
45 }
46 
47 /* Install this scrub-by-handle inode and prepare it for scrubbing. */
48 static inline int
49 xchk_install_handle_iscrub(
50 	struct xfs_scrub	*sc,
51 	struct xfs_inode	*ip)
52 {
53 	int			error;
54 
55 	error = xchk_install_handle_inode(sc, ip);
56 	if (error)
57 		return error;
58 
59 	return xchk_prepare_iscrub(sc);
60 }
61 
62 /*
63  * Grab total control of the inode metadata.  In the best case, we grab the
64  * incore inode and take all locks on it.  If the incore inode cannot be
65  * constructed due to corruption problems, lock the AGI so that we can single
66  * step the loading process to fix everything that can go wrong.
67  */
68 int
69 xchk_setup_inode(
70 	struct xfs_scrub	*sc)
71 {
72 	struct xfs_imap		imap;
73 	struct xfs_inode	*ip;
74 	struct xfs_mount	*mp = sc->mp;
75 	struct xfs_inode	*ip_in = XFS_I(file_inode(sc->file));
76 	struct xfs_buf		*agi_bp;
77 	struct xfs_perag	*pag;
78 	xfs_agnumber_t		agno = XFS_INO_TO_AGNO(mp, sc->sm->sm_ino);
79 	int			error;
80 
81 	if (xchk_need_intent_drain(sc))
82 		xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN);
83 
84 	/* We want to scan the opened inode, so lock it and exit. */
85 	if (sc->sm->sm_ino == 0 || sc->sm->sm_ino == ip_in->i_ino) {
86 		sc->ip = ip_in;
87 		return xchk_prepare_iscrub(sc);
88 	}
89 
90 	/* Reject internal metadata files and obviously bad inode numbers. */
91 	if (xfs_internal_inum(mp, sc->sm->sm_ino))
92 		return -ENOENT;
93 	if (!xfs_verify_ino(sc->mp, sc->sm->sm_ino))
94 		return -ENOENT;
95 
96 	/* Try a regular untrusted iget. */
97 	error = xchk_iget(sc, sc->sm->sm_ino, &ip);
98 	if (!error)
99 		return xchk_install_handle_iscrub(sc, ip);
100 	if (error == -ENOENT)
101 		return error;
102 	if (error != -EFSCORRUPTED && error != -EFSBADCRC && error != -EINVAL)
103 		goto out_error;
104 
105 	/*
106 	 * EINVAL with IGET_UNTRUSTED probably means one of several things:
107 	 * userspace gave us an inode number that doesn't correspond to fs
108 	 * space; the inode btree lacks a record for this inode; or there is
109 	 * a record, and it says this inode is free.
110 	 *
111 	 * EFSCORRUPTED/EFSBADCRC could mean that the inode was mappable, but
112 	 * some other metadata corruption (e.g. inode forks) prevented
113 	 * instantiation of the incore inode.  Or it could mean the inobt is
114 	 * corrupt.
115 	 *
116 	 * We want to look up this inode in the inobt directly to distinguish
117 	 * three different scenarios: (1) the inobt says the inode is free,
118 	 * in which case there's nothing to do; (2) the inobt is corrupt so we
119 	 * should flag the corruption and exit to userspace to let it fix the
120 	 * inobt; and (3) the inobt says the inode is allocated, but loading it
121 	 * failed due to corruption.
122 	 *
123 	 * Allocate a transaction and grab the AGI to prevent inobt activity in
124 	 * this AG.  Retry the iget in case someone allocated a new inode after
125 	 * the first iget failed.
126 	 */
127 	error = xchk_trans_alloc(sc, 0);
128 	if (error)
129 		goto out_error;
130 
131 	error = xchk_iget_agi(sc, sc->sm->sm_ino, &agi_bp, &ip);
132 	if (error == 0) {
133 		/* Actually got the incore inode, so install it and proceed. */
134 		xchk_trans_cancel(sc);
135 		return xchk_install_handle_iscrub(sc, ip);
136 	}
137 	if (error == -ENOENT)
138 		goto out_gone;
139 	if (error != -EFSCORRUPTED && error != -EFSBADCRC && error != -EINVAL)
140 		goto out_cancel;
141 
142 	/* Ensure that we have protected against inode allocation/freeing. */
143 	if (agi_bp == NULL) {
144 		ASSERT(agi_bp != NULL);
145 		error = -ECANCELED;
146 		goto out_cancel;
147 	}
148 
149 	/*
150 	 * Untrusted iget failed a second time.  Let's try an inobt lookup.
151 	 * If the inobt doesn't think this is an allocated inode then we'll
152 	 * return ENOENT to signal that the check can be skipped.
153 	 *
154 	 * If the lookup signals corruption, we'll mark this inode corrupt and
155 	 * exit to userspace.  There's little chance of fixing anything until
156 	 * the inobt is straightened out, but there's nothing we can do here.
157 	 *
158 	 * If the lookup encounters a runtime error, exit to userspace.
159 	 */
160 	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, sc->sm->sm_ino));
161 	if (!pag) {
162 		error = -EFSCORRUPTED;
163 		goto out_cancel;
164 	}
165 
166 	error = xfs_imap(pag, sc->tp, sc->sm->sm_ino, &imap,
167 			XFS_IGET_UNTRUSTED);
168 	xfs_perag_put(pag);
169 	if (error == -EINVAL || error == -ENOENT)
170 		goto out_gone;
171 	if (error)
172 		goto out_cancel;
173 
174 	/*
175 	 * The lookup succeeded.  Chances are the ondisk inode is corrupt and
176 	 * preventing iget from reading it.  Retain the scrub transaction and
177 	 * the AGI buffer to prevent anyone from allocating or freeing inodes.
178 	 * This ensures that we preserve the inconsistency between the inobt
179 	 * saying the inode is allocated and the icache being unable to load
180 	 * the inode until we can flag the corruption in xchk_inode.  The
181 	 * scrub function has to note the corruption, since we're not really
182 	 * supposed to do that from the setup function.
183 	 */
184 	return 0;
185 
186 out_cancel:
187 	xchk_trans_cancel(sc);
188 out_error:
189 	trace_xchk_op_error(sc, agno, XFS_INO_TO_AGBNO(mp, sc->sm->sm_ino),
190 			error, __return_address);
191 	return error;
192 out_gone:
193 	/* The file is gone, so there's nothing to check. */
194 	xchk_trans_cancel(sc);
195 	return -ENOENT;
196 }
197 
198 /* Inode core */
199 
200 /* Validate di_extsize hint. */
201 STATIC void
202 xchk_inode_extsize(
203 	struct xfs_scrub	*sc,
204 	struct xfs_dinode	*dip,
205 	xfs_ino_t		ino,
206 	uint16_t		mode,
207 	uint16_t		flags)
208 {
209 	xfs_failaddr_t		fa;
210 	uint32_t		value = be32_to_cpu(dip->di_extsize);
211 
212 	fa = xfs_inode_validate_extsize(sc->mp, value, mode, flags);
213 	if (fa)
214 		xchk_ino_set_corrupt(sc, ino);
215 
216 	/*
217 	 * XFS allows a sysadmin to change the rt extent size when adding a rt
218 	 * section to a filesystem after formatting.  If there are any
219 	 * directories with extszinherit and rtinherit set, the hint could
220 	 * become misaligned with the new rextsize.  The verifier doesn't check
221 	 * this, because we allow rtinherit directories even without an rt
222 	 * device.  Flag this as an administrative warning since we will clean
223 	 * this up eventually.
224 	 */
225 	if ((flags & XFS_DIFLAG_RTINHERIT) &&
226 	    (flags & XFS_DIFLAG_EXTSZINHERIT) &&
227 	    value % sc->mp->m_sb.sb_rextsize > 0)
228 		xchk_ino_set_warning(sc, ino);
229 }
230 
231 /*
232  * Validate di_cowextsize hint.
233  *
234  * The rules are documented at xfs_ioctl_setattr_check_cowextsize().
235  * These functions must be kept in sync with each other.
236  */
237 STATIC void
238 xchk_inode_cowextsize(
239 	struct xfs_scrub	*sc,
240 	struct xfs_dinode	*dip,
241 	xfs_ino_t		ino,
242 	uint16_t		mode,
243 	uint16_t		flags,
244 	uint64_t		flags2)
245 {
246 	xfs_failaddr_t		fa;
247 
248 	fa = xfs_inode_validate_cowextsize(sc->mp,
249 			be32_to_cpu(dip->di_cowextsize), mode, flags,
250 			flags2);
251 	if (fa)
252 		xchk_ino_set_corrupt(sc, ino);
253 }
254 
255 /* Make sure the di_flags make sense for the inode. */
256 STATIC void
257 xchk_inode_flags(
258 	struct xfs_scrub	*sc,
259 	struct xfs_dinode	*dip,
260 	xfs_ino_t		ino,
261 	uint16_t		mode,
262 	uint16_t		flags)
263 {
264 	struct xfs_mount	*mp = sc->mp;
265 
266 	/* di_flags are all taken, last bit cannot be used */
267 	if (flags & ~XFS_DIFLAG_ANY)
268 		goto bad;
269 
270 	/* rt flags require rt device */
271 	if ((flags & XFS_DIFLAG_REALTIME) && !mp->m_rtdev_targp)
272 		goto bad;
273 
274 	/* new rt bitmap flag only valid for rbmino */
275 	if ((flags & XFS_DIFLAG_NEWRTBM) && ino != mp->m_sb.sb_rbmino)
276 		goto bad;
277 
278 	/* directory-only flags */
279 	if ((flags & (XFS_DIFLAG_RTINHERIT |
280 		     XFS_DIFLAG_EXTSZINHERIT |
281 		     XFS_DIFLAG_PROJINHERIT |
282 		     XFS_DIFLAG_NOSYMLINKS)) &&
283 	    !S_ISDIR(mode))
284 		goto bad;
285 
286 	/* file-only flags */
287 	if ((flags & (XFS_DIFLAG_REALTIME | FS_XFLAG_EXTSIZE)) &&
288 	    !S_ISREG(mode))
289 		goto bad;
290 
291 	/* filestreams and rt make no sense */
292 	if ((flags & XFS_DIFLAG_FILESTREAM) && (flags & XFS_DIFLAG_REALTIME))
293 		goto bad;
294 
295 	return;
296 bad:
297 	xchk_ino_set_corrupt(sc, ino);
298 }
299 
300 /* Make sure the di_flags2 make sense for the inode. */
301 STATIC void
302 xchk_inode_flags2(
303 	struct xfs_scrub	*sc,
304 	struct xfs_dinode	*dip,
305 	xfs_ino_t		ino,
306 	uint16_t		mode,
307 	uint16_t		flags,
308 	uint64_t		flags2)
309 {
310 	struct xfs_mount	*mp = sc->mp;
311 
312 	/* Unknown di_flags2 could be from a future kernel */
313 	if (flags2 & ~XFS_DIFLAG2_ANY)
314 		xchk_ino_set_warning(sc, ino);
315 
316 	/* reflink flag requires reflink feature */
317 	if ((flags2 & XFS_DIFLAG2_REFLINK) &&
318 	    !xfs_has_reflink(mp))
319 		goto bad;
320 
321 	/* cowextsize flag is checked w.r.t. mode separately */
322 
323 	/* file/dir-only flags */
324 	if ((flags2 & XFS_DIFLAG2_DAX) && !(S_ISREG(mode) || S_ISDIR(mode)))
325 		goto bad;
326 
327 	/* file-only flags */
328 	if ((flags2 & XFS_DIFLAG2_REFLINK) && !S_ISREG(mode))
329 		goto bad;
330 
331 	/* realtime and reflink make no sense, currently */
332 	if ((flags & XFS_DIFLAG_REALTIME) && (flags2 & XFS_DIFLAG2_REFLINK))
333 		goto bad;
334 
335 	/* no bigtime iflag without the bigtime feature */
336 	if (xfs_dinode_has_bigtime(dip) && !xfs_has_bigtime(mp))
337 		goto bad;
338 
339 	return;
340 bad:
341 	xchk_ino_set_corrupt(sc, ino);
342 }
343 
344 static inline void
345 xchk_dinode_nsec(
346 	struct xfs_scrub	*sc,
347 	xfs_ino_t		ino,
348 	struct xfs_dinode	*dip,
349 	const xfs_timestamp_t	ts)
350 {
351 	struct timespec64	tv;
352 
353 	tv = xfs_inode_from_disk_ts(dip, ts);
354 	if (tv.tv_nsec < 0 || tv.tv_nsec >= NSEC_PER_SEC)
355 		xchk_ino_set_corrupt(sc, ino);
356 }
357 
358 /* Scrub all the ondisk inode fields. */
359 STATIC void
360 xchk_dinode(
361 	struct xfs_scrub	*sc,
362 	struct xfs_dinode	*dip,
363 	xfs_ino_t		ino)
364 {
365 	struct xfs_mount	*mp = sc->mp;
366 	size_t			fork_recs;
367 	unsigned long long	isize;
368 	uint64_t		flags2;
369 	xfs_extnum_t		nextents;
370 	xfs_extnum_t		naextents;
371 	prid_t			prid;
372 	uint16_t		flags;
373 	uint16_t		mode;
374 
375 	flags = be16_to_cpu(dip->di_flags);
376 	if (dip->di_version >= 3)
377 		flags2 = be64_to_cpu(dip->di_flags2);
378 	else
379 		flags2 = 0;
380 
381 	/* di_mode */
382 	mode = be16_to_cpu(dip->di_mode);
383 	switch (mode & S_IFMT) {
384 	case S_IFLNK:
385 	case S_IFREG:
386 	case S_IFDIR:
387 	case S_IFCHR:
388 	case S_IFBLK:
389 	case S_IFIFO:
390 	case S_IFSOCK:
391 		/* mode is recognized */
392 		break;
393 	default:
394 		xchk_ino_set_corrupt(sc, ino);
395 		break;
396 	}
397 
398 	/* v1/v2 fields */
399 	switch (dip->di_version) {
400 	case 1:
401 		/*
402 		 * We autoconvert v1 inodes into v2 inodes on writeout,
403 		 * so just mark this inode for preening.
404 		 */
405 		xchk_ino_set_preen(sc, ino);
406 		prid = 0;
407 		break;
408 	case 2:
409 	case 3:
410 		if (dip->di_onlink != 0)
411 			xchk_ino_set_corrupt(sc, ino);
412 
413 		if (dip->di_mode == 0 && sc->ip)
414 			xchk_ino_set_corrupt(sc, ino);
415 
416 		if (dip->di_projid_hi != 0 &&
417 		    !xfs_has_projid32(mp))
418 			xchk_ino_set_corrupt(sc, ino);
419 
420 		prid = be16_to_cpu(dip->di_projid_lo);
421 		break;
422 	default:
423 		xchk_ino_set_corrupt(sc, ino);
424 		return;
425 	}
426 
427 	if (xfs_has_projid32(mp))
428 		prid |= (prid_t)be16_to_cpu(dip->di_projid_hi) << 16;
429 
430 	/*
431 	 * di_uid/di_gid -- -1 isn't invalid, but there's no way that
432 	 * userspace could have created that.
433 	 */
434 	if (dip->di_uid == cpu_to_be32(-1U) ||
435 	    dip->di_gid == cpu_to_be32(-1U))
436 		xchk_ino_set_warning(sc, ino);
437 
438 	/*
439 	 * project id of -1 isn't supposed to be valid, but the kernel didn't
440 	 * always validate that.
441 	 */
442 	if (prid == -1U)
443 		xchk_ino_set_warning(sc, ino);
444 
445 	/* di_format */
446 	switch (dip->di_format) {
447 	case XFS_DINODE_FMT_DEV:
448 		if (!S_ISCHR(mode) && !S_ISBLK(mode) &&
449 		    !S_ISFIFO(mode) && !S_ISSOCK(mode))
450 			xchk_ino_set_corrupt(sc, ino);
451 		break;
452 	case XFS_DINODE_FMT_LOCAL:
453 		if (!S_ISDIR(mode) && !S_ISLNK(mode))
454 			xchk_ino_set_corrupt(sc, ino);
455 		break;
456 	case XFS_DINODE_FMT_EXTENTS:
457 		if (!S_ISREG(mode) && !S_ISDIR(mode) && !S_ISLNK(mode))
458 			xchk_ino_set_corrupt(sc, ino);
459 		break;
460 	case XFS_DINODE_FMT_BTREE:
461 		if (!S_ISREG(mode) && !S_ISDIR(mode))
462 			xchk_ino_set_corrupt(sc, ino);
463 		break;
464 	case XFS_DINODE_FMT_UUID:
465 	default:
466 		xchk_ino_set_corrupt(sc, ino);
467 		break;
468 	}
469 
470 	/* di_[amc]time.nsec */
471 	xchk_dinode_nsec(sc, ino, dip, dip->di_atime);
472 	xchk_dinode_nsec(sc, ino, dip, dip->di_mtime);
473 	xchk_dinode_nsec(sc, ino, dip, dip->di_ctime);
474 
475 	/*
476 	 * di_size.  xfs_dinode_verify checks for things that screw up
477 	 * the VFS such as the upper bit being set and zero-length
478 	 * symlinks/directories, but we can do more here.
479 	 */
480 	isize = be64_to_cpu(dip->di_size);
481 	if (isize & (1ULL << 63))
482 		xchk_ino_set_corrupt(sc, ino);
483 
484 	/* Devices, fifos, and sockets must have zero size */
485 	if (!S_ISDIR(mode) && !S_ISREG(mode) && !S_ISLNK(mode) && isize != 0)
486 		xchk_ino_set_corrupt(sc, ino);
487 
488 	/* Directories can't be larger than the data section size (32G) */
489 	if (S_ISDIR(mode) && (isize == 0 || isize >= XFS_DIR2_SPACE_SIZE))
490 		xchk_ino_set_corrupt(sc, ino);
491 
492 	/* Symlinks can't be larger than SYMLINK_MAXLEN */
493 	if (S_ISLNK(mode) && (isize == 0 || isize >= XFS_SYMLINK_MAXLEN))
494 		xchk_ino_set_corrupt(sc, ino);
495 
496 	/*
497 	 * Warn if the running kernel can't handle the kinds of offsets
498 	 * needed to deal with the file size.  In other words, if the
499 	 * pagecache can't cache all the blocks in this file due to
500 	 * overly large offsets, flag the inode for admin review.
501 	 */
502 	if (isize > mp->m_super->s_maxbytes)
503 		xchk_ino_set_warning(sc, ino);
504 
505 	/* di_nblocks */
506 	if (flags2 & XFS_DIFLAG2_REFLINK) {
507 		; /* nblocks can exceed dblocks */
508 	} else if (flags & XFS_DIFLAG_REALTIME) {
509 		/*
510 		 * nblocks is the sum of data extents (in the rtdev),
511 		 * attr extents (in the datadev), and both forks' bmbt
512 		 * blocks (in the datadev).  This clumsy check is the
513 		 * best we can do without cross-referencing with the
514 		 * inode forks.
515 		 */
516 		if (be64_to_cpu(dip->di_nblocks) >=
517 		    mp->m_sb.sb_dblocks + mp->m_sb.sb_rblocks)
518 			xchk_ino_set_corrupt(sc, ino);
519 	} else {
520 		if (be64_to_cpu(dip->di_nblocks) >= mp->m_sb.sb_dblocks)
521 			xchk_ino_set_corrupt(sc, ino);
522 	}
523 
524 	xchk_inode_flags(sc, dip, ino, mode, flags);
525 
526 	xchk_inode_extsize(sc, dip, ino, mode, flags);
527 
528 	nextents = xfs_dfork_data_extents(dip);
529 	naextents = xfs_dfork_attr_extents(dip);
530 
531 	/* di_nextents */
532 	fork_recs =  XFS_DFORK_DSIZE(dip, mp) / sizeof(struct xfs_bmbt_rec);
533 	switch (dip->di_format) {
534 	case XFS_DINODE_FMT_EXTENTS:
535 		if (nextents > fork_recs)
536 			xchk_ino_set_corrupt(sc, ino);
537 		break;
538 	case XFS_DINODE_FMT_BTREE:
539 		if (nextents <= fork_recs)
540 			xchk_ino_set_corrupt(sc, ino);
541 		break;
542 	default:
543 		if (nextents != 0)
544 			xchk_ino_set_corrupt(sc, ino);
545 		break;
546 	}
547 
548 	/* di_forkoff */
549 	if (XFS_DFORK_APTR(dip) >= (char *)dip + mp->m_sb.sb_inodesize)
550 		xchk_ino_set_corrupt(sc, ino);
551 	if (naextents != 0 && dip->di_forkoff == 0)
552 		xchk_ino_set_corrupt(sc, ino);
553 	if (dip->di_forkoff == 0 && dip->di_aformat != XFS_DINODE_FMT_EXTENTS)
554 		xchk_ino_set_corrupt(sc, ino);
555 
556 	/* di_aformat */
557 	if (dip->di_aformat != XFS_DINODE_FMT_LOCAL &&
558 	    dip->di_aformat != XFS_DINODE_FMT_EXTENTS &&
559 	    dip->di_aformat != XFS_DINODE_FMT_BTREE)
560 		xchk_ino_set_corrupt(sc, ino);
561 
562 	/* di_anextents */
563 	fork_recs =  XFS_DFORK_ASIZE(dip, mp) / sizeof(struct xfs_bmbt_rec);
564 	switch (dip->di_aformat) {
565 	case XFS_DINODE_FMT_EXTENTS:
566 		if (naextents > fork_recs)
567 			xchk_ino_set_corrupt(sc, ino);
568 		break;
569 	case XFS_DINODE_FMT_BTREE:
570 		if (naextents <= fork_recs)
571 			xchk_ino_set_corrupt(sc, ino);
572 		break;
573 	default:
574 		if (naextents != 0)
575 			xchk_ino_set_corrupt(sc, ino);
576 	}
577 
578 	if (dip->di_version >= 3) {
579 		xchk_dinode_nsec(sc, ino, dip, dip->di_crtime);
580 		xchk_inode_flags2(sc, dip, ino, mode, flags, flags2);
581 		xchk_inode_cowextsize(sc, dip, ino, mode, flags,
582 				flags2);
583 	}
584 }
585 
586 /*
587  * Make sure the finobt doesn't think this inode is free.
588  * We don't have to check the inobt ourselves because we got the inode via
589  * IGET_UNTRUSTED, which checks the inobt for us.
590  */
591 static void
592 xchk_inode_xref_finobt(
593 	struct xfs_scrub		*sc,
594 	xfs_ino_t			ino)
595 {
596 	struct xfs_inobt_rec_incore	rec;
597 	xfs_agino_t			agino;
598 	int				has_record;
599 	int				error;
600 
601 	if (!sc->sa.fino_cur || xchk_skip_xref(sc->sm))
602 		return;
603 
604 	agino = XFS_INO_TO_AGINO(sc->mp, ino);
605 
606 	/*
607 	 * Try to get the finobt record.  If we can't get it, then we're
608 	 * in good shape.
609 	 */
610 	error = xfs_inobt_lookup(sc->sa.fino_cur, agino, XFS_LOOKUP_LE,
611 			&has_record);
612 	if (!xchk_should_check_xref(sc, &error, &sc->sa.fino_cur) ||
613 	    !has_record)
614 		return;
615 
616 	error = xfs_inobt_get_rec(sc->sa.fino_cur, &rec, &has_record);
617 	if (!xchk_should_check_xref(sc, &error, &sc->sa.fino_cur) ||
618 	    !has_record)
619 		return;
620 
621 	/*
622 	 * Otherwise, make sure this record either doesn't cover this inode,
623 	 * or that it does but it's marked present.
624 	 */
625 	if (rec.ir_startino > agino ||
626 	    rec.ir_startino + XFS_INODES_PER_CHUNK <= agino)
627 		return;
628 
629 	if (rec.ir_free & XFS_INOBT_MASK(agino - rec.ir_startino))
630 		xchk_btree_xref_set_corrupt(sc, sc->sa.fino_cur, 0);
631 }
632 
633 /* Cross reference the inode fields with the forks. */
634 STATIC void
635 xchk_inode_xref_bmap(
636 	struct xfs_scrub	*sc,
637 	struct xfs_dinode	*dip)
638 {
639 	xfs_extnum_t		nextents;
640 	xfs_filblks_t		count;
641 	xfs_filblks_t		acount;
642 	int			error;
643 
644 	if (xchk_skip_xref(sc->sm))
645 		return;
646 
647 	/* Walk all the extents to check nextents/naextents/nblocks. */
648 	error = xfs_bmap_count_blocks(sc->tp, sc->ip, XFS_DATA_FORK,
649 			&nextents, &count);
650 	if (!xchk_should_check_xref(sc, &error, NULL))
651 		return;
652 	if (nextents < xfs_dfork_data_extents(dip))
653 		xchk_ino_xref_set_corrupt(sc, sc->ip->i_ino);
654 
655 	error = xfs_bmap_count_blocks(sc->tp, sc->ip, XFS_ATTR_FORK,
656 			&nextents, &acount);
657 	if (!xchk_should_check_xref(sc, &error, NULL))
658 		return;
659 	if (nextents != xfs_dfork_attr_extents(dip))
660 		xchk_ino_xref_set_corrupt(sc, sc->ip->i_ino);
661 
662 	/* Check nblocks against the inode. */
663 	if (count + acount != be64_to_cpu(dip->di_nblocks))
664 		xchk_ino_xref_set_corrupt(sc, sc->ip->i_ino);
665 }
666 
667 /* Cross-reference with the other btrees. */
668 STATIC void
669 xchk_inode_xref(
670 	struct xfs_scrub	*sc,
671 	xfs_ino_t		ino,
672 	struct xfs_dinode	*dip)
673 {
674 	xfs_agnumber_t		agno;
675 	xfs_agblock_t		agbno;
676 	int			error;
677 
678 	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
679 		return;
680 
681 	agno = XFS_INO_TO_AGNO(sc->mp, ino);
682 	agbno = XFS_INO_TO_AGBNO(sc->mp, ino);
683 
684 	error = xchk_ag_init_existing(sc, agno, &sc->sa);
685 	if (!xchk_xref_process_error(sc, agno, agbno, &error))
686 		goto out_free;
687 
688 	xchk_xref_is_used_space(sc, agbno, 1);
689 	xchk_inode_xref_finobt(sc, ino);
690 	xchk_xref_is_only_owned_by(sc, agbno, 1, &XFS_RMAP_OINFO_INODES);
691 	xchk_xref_is_not_shared(sc, agbno, 1);
692 	xchk_xref_is_not_cow_staging(sc, agbno, 1);
693 	xchk_inode_xref_bmap(sc, dip);
694 
695 out_free:
696 	xchk_ag_free(sc, &sc->sa);
697 }
698 
699 /*
700  * If the reflink iflag disagrees with a scan for shared data fork extents,
701  * either flag an error (shared extents w/ no flag) or a preen (flag set w/o
702  * any shared extents).  We already checked for reflink iflag set on a non
703  * reflink filesystem.
704  */
705 static void
706 xchk_inode_check_reflink_iflag(
707 	struct xfs_scrub	*sc,
708 	xfs_ino_t		ino)
709 {
710 	struct xfs_mount	*mp = sc->mp;
711 	bool			has_shared;
712 	int			error;
713 
714 	if (!xfs_has_reflink(mp))
715 		return;
716 
717 	error = xfs_reflink_inode_has_shared_extents(sc->tp, sc->ip,
718 			&has_shared);
719 	if (!xchk_xref_process_error(sc, XFS_INO_TO_AGNO(mp, ino),
720 			XFS_INO_TO_AGBNO(mp, ino), &error))
721 		return;
722 	if (xfs_is_reflink_inode(sc->ip) && !has_shared)
723 		xchk_ino_set_preen(sc, ino);
724 	else if (!xfs_is_reflink_inode(sc->ip) && has_shared)
725 		xchk_ino_set_corrupt(sc, ino);
726 }
727 
728 /* Scrub an inode. */
729 int
730 xchk_inode(
731 	struct xfs_scrub	*sc)
732 {
733 	struct xfs_dinode	di;
734 	int			error = 0;
735 
736 	/*
737 	 * If sc->ip is NULL, that means that the setup function called
738 	 * xfs_iget to look up the inode.  xfs_iget returned a EFSCORRUPTED
739 	 * and a NULL inode, so flag the corruption error and return.
740 	 */
741 	if (!sc->ip) {
742 		xchk_ino_set_corrupt(sc, sc->sm->sm_ino);
743 		return 0;
744 	}
745 
746 	/* Scrub the inode core. */
747 	xfs_inode_to_disk(sc->ip, &di, 0);
748 	xchk_dinode(sc, &di, sc->ip->i_ino);
749 	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
750 		goto out;
751 
752 	/*
753 	 * Look for discrepancies between file's data blocks and the reflink
754 	 * iflag.  We already checked the iflag against the file mode when
755 	 * we scrubbed the dinode.
756 	 */
757 	if (S_ISREG(VFS_I(sc->ip)->i_mode))
758 		xchk_inode_check_reflink_iflag(sc, sc->ip->i_ino);
759 
760 	xchk_inode_xref(sc, sc->ip->i_ino, &di);
761 out:
762 	return error;
763 }
764